The present invention relates to a novel aromatic polyester resins having an improved heat resistance with improved water resistance and mechanical strength and a process for the preparation thereof.
Aromatic polyesters consisting of aromatic dicarboxylic acids and bivalent phenol compounds have been known for many years. Also, as processes for preparing them, an interfacial polycondensation process, a solution polymerization process, a melt polymerization process and so on have been known.
Aromatic polyesters have excellent heat resistance and mechanical property, and are useful substances as molding materials. In general, however, the aromatic polyesters have the property that the ester linkage is hydrolyzed, and particularly the alkali resistance is very poor. Further, although the aromatic polyesters have an excellent heat resistance, the heat resistance is not always satisfactory when the polyesters are used in the electric and electronic fields, and for instance, the heat resistance of the polyesters in molten solder is not sufficient. Therefore, it has been required to further raise the usable temperature region for the aromatic polyesters.